Mercy Hospital purchased a special x-ray machine. The machine, which cost $623,120, was expected to last 10 years, with an estimated residual value of $63,120. After two years of operation (and depreciation charges using the straight-line method), it became evident that the x-ray machine would last a total of only seven years. The estimated residual value, however, would remain the same. Given this information, determine the new depreciation charge for the third year on the basis of the revised estimated useful life.